Rainbow Cereal Bars {3 Ingredients}

Quick and easy cereal bars recipe, homemade with 3 simple ingredients. These no bake rainbow bars are full of Froot Loops and marshmallows. Perfect for rainbow parties or St.Patrick’s Day!

These are actually a spin on the classic rice krispie treats. Truth be told, I am not too crazy about rice krispie treats because their texture is weird but these treats have a totally different texture. They are crispy and crunchy unlike the classic, which are soft and chewy. Be prepared to land in a sugar coma after having a few nibbles because these cuties are sweet! I actually served these at my son’s colorful shapes birthday party and the kids loved them! These would also be great for serving at rainbow themed birthday parties or even St.Patrick’s Day. These Smores Bars {No Bake}, No Bake Breakfast Muffins, Easy Cereal Cookies {With Froot Loops}, Easy Cereal Cake {With Trix}, and Rainbow Cereal Balls {No Bake} are all made from different cereals just like these bars, and would also make fantastic birthday party treats.

Easy Cereal Bars With Froot Loops on Sheet of Paper- Overhead Shot

Key ingredients

  • Cereal– Fruit Loops were the perfect choice.
  • Marshmallows– Mini are best.

How to make easy cereal bars recipe from scratch?

  1. Microwave butter and marshmallows– Until everything is melted.
  2. Add cereal– Mix everything.
  3. Spread on a cookie tray– Sprayed with oil.
  4. Chill– Then cut. Enjoy!

Are these bars a healthy snack?

 Probably not, because they are a sugary cereal to begin with, and then I covered them in even more sugar with the addition of marshmallows. Not the healthiest, but certainly delicious.

Marshmallow Bars on Textured Gray Background

Add-ins for marshmallow bars snack

  • Chocolate chips– Mini white chocolate chips would be delicious.
  • Chopped up candy bars– Such as Twix, m&ms, Kit Kats, or another favorite.
  • Nuts– Such as chopped peanuts, cashews, or almonds.
  • Finely chopped dried fruits– Such as apricots, mangoes, cherries, or blueberries.
  • Sprinkles– Use colorful pearls, jimmies, or themed ones such as stars, rainbows, etc.
  • Marshmallows– I know it seems redundant, but add in some mini marshmallows when you mix in the cereal. This allows there to be some unmelted marshmallows within the bars. It’s a fun texture and look.


Use other cereals– Such as Honey Grahams, Cocoa Puffs, Reese’s puffs, Cheerios, Fruity Pebbles, or Lucky Charms.

Add a drizzle– Such as a white, milk, or dark chocolate drizzle on top of the bars.

Add an extract– Such as vanilla extract to enhance the flavor more.

Use shaped cutters– Like stars, circles, or another shape to match the theme of your event.

Mix in some nut butter– Such as peanut, almond, sunflower, or cashew butter.

Use flavored marshmallows– Such as strawberry, or other fruit flavors that would go well with the fruit loops cereal.

Tips and techniques for rainbow bars

Pan must be sprayed very generously with oil– Or else the mixture will stick to it and not come out. It is best to oil your mixing spoon and spatula too. You will have to re-apply the oil a few times. I use a spray bottle filled with oil. Just make sure to use neutral tasting oil like canola or vegetable oil because you don’t want to taste it on the bars.

Use a sharp knife to cut bars– I didn’t want proper square or rectangle bars but that’s something you can easily do with a sharp knife. I wanted more artistic shard-like pieces. 

How to microwave ingredients? Be sure to remove the bowl from the microwave every 30 seconds and give everything a quick stir. Repeat this until the mixture is completely melted.

Use unsalted butter– To prevent the bars from becoming too salty.

Chill bars before cutting– Because this allows you to make a clean cut.

Froot Loops Rainbow Bars on Textured Gray Background


Make ahead Instructions– These can be made a day in advance, and stored in a sealed container at room temp.

Room temperature– In a sealed container for up to 1 week.

Freeze– In a freezer safe container for up to 1 month. Once the bars are cool, cut and place them in a sealed airtight container, making sure the layers are separated by wax paper. When you are ready to serve them, let them thaw at room temperature for 20-30 minutes.

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Easy Cereal Bars (Rainbow Bars)

Prep Time: 10 minutes
Chill time: 1 hour
Total Time: 1 hour 10 minutes
Quick and easy cereal bars recipe, homemade with 3 simple ingredients. These no bake rainbow bars are full of Froot Loops and marshmallows. Perfect for rainbow parties or St.Patrick's Day!
Yield: 9 Bars


  • 1/4 cup Butter, Unsalted
  • 6 cups Marshmallows, Mini
  • 8 cups Cereal, Such as Froot Loops


  • In a deep mixing bowl, add the butter and marshmallows.
  • Heat in the microwave until everything is melted. Be sure to remove the bowl from the microwave every 30 seconds and give everything a quick stir.
  • Once you have a smooth marshmallow mixture, dump the cereal into the bowl and mix everything.
  • Now, spread this fruit loops mixture on a cookie tray that’s been sprayed generously with oil.
  • Chill in the refrigerator for an hour and then cut into bars or shards like I did. Enjoy!


  • Read all my tips above.
  • Leftovers can be stored in a sealed container at room temperature for up to 1 week. 


Calories: 286kcal, Carbohydrates: 62g, Protein: 3g, Fat: 5g, Saturated Fat: 3g, Cholesterol: 12mg, Sodium: 268mg, Potassium: 181mg, Fiber: 5g, Sugar: 31g, Vitamin A: 940IU, Calcium: 21mg, Iron: 8.7mg
Course: Dessert
Cuisine: American
Calories: 286
Author: Abeer Rizvi

3 comments on “Rainbow Cereal Bars {3 Ingredients}”

  1. These look so perfect. Unicorn approved! I know this post is from a while ago but it’s new to me! 5 stars

  2. Do these treats need to be refrigerated?4 stars

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